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Influence Of The Subject's Attitude

One continually meets such queries as, "How do you know the subject did his best?"
"Possibly the child was nervous or frightened," or, "Perhaps incorrect answers were
purposely given." All such objections may be disposed of by saying that the
competent examiner can easily control the experiment in such a way that
embarrassment is soon replaced by self-confidence, and in such a way
that effort is kept at its maximum. As for mischievous deception, it
would be a poor clinicist who could not recognize and deal with the
little that is likely to arise.

Cautions regarding embarrassment, fatigue, fright, illness, etc. are
given in Chapter IX. Most of the errors which have been reported along
this line are such as can nearly always be avoided by ordinary prudence,
coupled with a little power of observation.[38] We must not charge the
mistakes of untrained and indiscreet examiners against the validity of
the method itself.

[38] See, for example, the rather ludicrous "errors" of the Binet method
reported in _The Psychological Clinic_ for 1915, pp. 140 _ff._ and
167 _ff._

It is possibly true that even if the examiner is tactful and prudent an
unfavorable attitude on the part of the subject may occasionally affect
the results of a test to some extent, but it ought not seriously to
invalidate one examination out of five hundred. The greatest danger is
in the case of a young subject who has been recently arrested and
brought before a court. Even here a little common sense and scientific
insight should enable one to guard against a mistaken diagnosis.